Ok so to be sure

Radar is an object-detection system that uses waves to control the elevation, speed, and direction of objects. The antenna conducts radio waves or microwaves that bounce off any object in their way returning a small part of the wave’s energy to an antenna.

Radar are used all around us, although it is invisible.
If we would see the waves emitted by the radars, probably we would be surrounded by many waves. Though some waves would be smaller than others.

Radars are generally used to detect property invasion, or any type of unknown obstacle. Though it's also used to detect aircrafts, ships, spacecraft, missile, and weather formations.

The story of radar starts with experiments by Heinrich Hertz in the late 19th period that showed that radio waves were imitated by metallic objects. However, in the 20th century the German Christian Hülsmeyer created a detection device ship to avoid crashes in the fog.

They can protect our countries from invasions. They can also be useful for detecting the speed of a tennis ball , or the speed of a car. Radars allow objects to travel farther evading obstacles that may end sinking ships or colliding with airplanes while getting on the wrong route.

As I said because of radars we can use transports as boats that may not be able to in fog. In the place of planes we could not travel because airplanes are constantly depending on radars to see how they go. Also radars are crucial for submarines because thats how they manage them self in the imperfection of the ocean.

Radars may affect the government or even countries relationships given that this way they can see who enters the country and who leaves it. Also this gives them the advantage to detect if there is any missile or conflict with another place.

Governments start depending on technology such as radars giving them a tendency to see who is entering. This terrain conflict would make countries doubt with other countries what space is actually of theirs creating a country that wants more power.

Low-frequency radar is locater which customs frequencies inferior than 1 GHz, as different to the usual radar groups, which variety from 2 GHz and up, and the extreme is 40 GHz. The Radar cross unit of any target varies on the radar communicated frequency.

Short wavelength radars are more effective in detecting small units as mist precipitations and drizzle drops.The main advantage of using longer wavelengths is that absorption by the overriding units is radically reduced. This means that a distant thunderstorm behind a closer thunderstorm will appear on the radar fast.